From 0b2973aef262801e60b1b62de89a105bc3d5dc76 Mon Sep 17 00:00:00 2001 From: Nate Begeman Date: Fri, 21 Oct 2005 01:52:20 +0000 Subject: [PATCH] Kill some now-dead code. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23857 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/Alpha/AlphaISelPattern.cpp | 159 -------------------------- 1 file changed, 159 deletions(-) diff --git a/lib/Target/Alpha/AlphaISelPattern.cpp b/lib/Target/Alpha/AlphaISelPattern.cpp index e5232457254..2f04646bfdc 100644 --- a/lib/Target/Alpha/AlphaISelPattern.cpp +++ b/lib/Target/Alpha/AlphaISelPattern.cpp @@ -235,152 +235,6 @@ static bool factorize(int v[], int res[], int size, uint64_t c) } -//Shamelessly adapted from PPC32 -// Structure used to return the necessary information to codegen an SDIV as -// a multiply. -struct ms { - int64_t m; // magic number - int64_t s; // shift amount -}; - -struct mu { - uint64_t m; // magic number - int64_t a; // add indicator - int64_t s; // shift amount -}; - -/// magic - calculate the magic numbers required to codegen an integer sdiv as -/// a sequence of multiply and shifts. Requires that the divisor not be 0, 1, -/// or -1. -static struct ms magic(int64_t d) { - int64_t p; - uint64_t ad, anc, delta, q1, r1, q2, r2, t; - const uint64_t two63 = 9223372036854775808ULL; // 2^63 - struct ms mag; - - ad = llabs(d); - t = two63 + ((uint64_t)d >> 63); - anc = t - 1 - t%ad; // absolute value of nc - p = 63; // initialize p - q1 = two63/anc; // initialize q1 = 2p/abs(nc) - r1 = two63 - q1*anc; // initialize r1 = rem(2p,abs(nc)) - q2 = two63/ad; // initialize q2 = 2p/abs(d) - r2 = two63 - q2*ad; // initialize r2 = rem(2p,abs(d)) - do { - p = p + 1; - q1 = 2*q1; // update q1 = 2p/abs(nc) - r1 = 2*r1; // update r1 = rem(2p/abs(nc)) - if (r1 >= anc) { // must be unsigned comparison - q1 = q1 + 1; - r1 = r1 - anc; - } - q2 = 2*q2; // update q2 = 2p/abs(d) - r2 = 2*r2; // update r2 = rem(2p/abs(d)) - if (r2 >= ad) { // must be unsigned comparison - q2 = q2 + 1; - r2 = r2 - ad; - } - delta = ad - r2; - } while (q1 < delta || (q1 == delta && r1 == 0)); - - mag.m = q2 + 1; - if (d < 0) mag.m = -mag.m; // resulting magic number - mag.s = p - 64; // resulting shift - return mag; -} - -/// magicu - calculate the magic numbers required to codegen an integer udiv as -/// a sequence of multiply, add and shifts. Requires that the divisor not be 0. -static struct mu magicu(uint64_t d) -{ - int64_t p; - uint64_t nc, delta, q1, r1, q2, r2; - struct mu magu; - magu.a = 0; // initialize "add" indicator - nc = - 1 - (-d)%d; - p = 63; // initialize p - q1 = 0x8000000000000000ull/nc; // initialize q1 = 2p/nc - r1 = 0x8000000000000000ull - q1*nc; // initialize r1 = rem(2p,nc) - q2 = 0x7FFFFFFFFFFFFFFFull/d; // initialize q2 = (2p-1)/d - r2 = 0x7FFFFFFFFFFFFFFFull - q2*d; // initialize r2 = rem((2p-1),d) - do { - p = p + 1; - if (r1 >= nc - r1 ) { - q1 = 2*q1 + 1; // update q1 - r1 = 2*r1 - nc; // update r1 - } - else { - q1 = 2*q1; // update q1 - r1 = 2*r1; // update r1 - } - if (r2 + 1 >= d - r2) { - if (q2 >= 0x7FFFFFFFFFFFFFFFull) magu.a = 1; - q2 = 2*q2 + 1; // update q2 - r2 = 2*r2 + 1 - d; // update r2 - } - else { - if (q2 >= 0x8000000000000000ull) magu.a = 1; - q2 = 2*q2; // update q2 - r2 = 2*r2 + 1; // update r2 - } - delta = d - 1 - r2; - } while (p < 64 && (q1 < delta || (q1 == delta && r1 == 0))); - magu.m = q2 + 1; // resulting magic number - magu.s = p - 64; // resulting shift - return magu; -} - -/// BuildSDIVSequence - Given an ISD::SDIV node expressing a divide by constant, -/// return a DAG expression to select that will generate the same value by -/// multiplying by a magic number. See: -/// -SDOperand AlphaISel::BuildSDIVSequence(SDOperand N) { - int64_t d = (int64_t)cast(N.getOperand(1))->getSignExtended(); - ms magics = magic(d); - // Multiply the numerator (operand 0) by the magic value - SDOperand Q = ISelDAG->getNode(ISD::MULHS, MVT::i64, N.getOperand(0), - ISelDAG->getConstant(magics.m, MVT::i64)); - // If d > 0 and m < 0, add the numerator - if (d > 0 && magics.m < 0) - Q = ISelDAG->getNode(ISD::ADD, MVT::i64, Q, N.getOperand(0)); - // If d < 0 and m > 0, subtract the numerator. - if (d < 0 && magics.m > 0) - Q = ISelDAG->getNode(ISD::SUB, MVT::i64, Q, N.getOperand(0)); - // Shift right algebraic if shift value is nonzero - if (magics.s > 0) - Q = ISelDAG->getNode(ISD::SRA, MVT::i64, Q, - ISelDAG->getConstant(magics.s, MVT::i64)); - // Extract the sign bit and add it to the quotient - SDOperand T = - ISelDAG->getNode(ISD::SRL, MVT::i64, Q, ISelDAG->getConstant(63, MVT::i64)); - return ISelDAG->getNode(ISD::ADD, MVT::i64, Q, T); -} - -/// BuildUDIVSequence - Given an ISD::UDIV node expressing a divide by constant, -/// return a DAG expression to select that will generate the same value by -/// multiplying by a magic number. See: -/// -SDOperand AlphaISel::BuildUDIVSequence(SDOperand N) { - unsigned d = - (unsigned)cast(N.getOperand(1))->getSignExtended(); - mu magics = magicu(d); - // Multiply the numerator (operand 0) by the magic value - SDOperand Q = ISelDAG->getNode(ISD::MULHU, MVT::i64, N.getOperand(0), - ISelDAG->getConstant(magics.m, MVT::i64)); - if (magics.a == 0) { - Q = ISelDAG->getNode(ISD::SRL, MVT::i64, Q, - ISelDAG->getConstant(magics.s, MVT::i64)); - } else { - SDOperand NPQ = ISelDAG->getNode(ISD::SUB, MVT::i64, N.getOperand(0), Q); - NPQ = ISelDAG->getNode(ISD::SRL, MVT::i64, NPQ, - ISelDAG->getConstant(1, MVT::i64)); - NPQ = ISelDAG->getNode(ISD::ADD, MVT::i64, NPQ, Q); - Q = ISelDAG->getNode(ISD::SRL, MVT::i64, NPQ, - ISelDAG->getConstant(magics.s-1, MVT::i64)); - } - return Q; -} - //These describe LDAx static const int IMM_LOW = -32768; static const int IMM_HIGH = 32767; @@ -1390,20 +1244,7 @@ unsigned AlphaISel::SelectExpr(SDOperand N) { } } //Else fall through - case ISD::UDIV: - { - if (isSIntImmediate(N.getOperand(1), SImm) && (SImm >= 2 || SImm <= -2)) - { - // If this is a divide by constant, we can emit code using some magic - // constants to implement it as a multiply instead. - ExprMap.erase(N); - if (opcode == ISD::SDIV) - return SelectExpr(BuildSDIVSequence(N)); - else - return SelectExpr(BuildUDIVSequence(N)); - } - } //else fall though case ISD::UREM: case ISD::SREM: { -- 2.34.1